COVID-19 vaccines linked to temporary increase in menstrual cycle length

Researchers funded by the National Institutes of Health (NIH) recently set out to investigate the relationship between menstrual cycle length and COVID-19 vaccination. “The findings were reassuring and reinforced the overall safety of COVID-19 vaccines, as it described a mild and temporary impact on the menstrual cycle length of vaccinated study participants. The authors found that the cycle length change was less than 1 day and temporary, resolving within two post-vaccination cycles,” said Dr. Amy Roskin, chief medical officer at The Pill Club — a digital health company — who was not involved in the study.The study appears in Obstetrics and Gynecology. Alison Edelman, a professor of obstetrics and gynecology at Oregon Health and Science University in Portland, and lead author of the study, told MNT: “Additional research is necessary to determine the causal relationship between COVID-19 vaccines and changes to menstrual cycle length.”“However, based on previous research that confirms a biological connection between the immune system and the reproductive system, we can hypothesize that vaccine-related menstrual disturbances may be related to the body’s acute immune response to the vaccine,” she added. The researchers found no clinically meaningful changes in menstrual cycle length associated with the COVID-19 vaccines.The researchers note that there are some limitations to their study.